JP6776114B2 - Hub dynamo - Google Patents

Description

The present invention relates to a hub dynamo.

Generators that generate electricity by rotating wheels are widely used to supply electric power to the headlights and taillights of bicycles. There are various types of such generators, but a so-called hub dynamo, which is attached to a hub shaft, is known.
Generally, a hub dynamo is provided with a rotor provided with a permanent magnet on the wheel side, and the rotor rotates around a stator provided on the hub shaft side to generate electricity with a coil provided in the stator.

As a stator in this hub dynamo, a plurality of first yokes and a plurality of second yokes are arranged on one side and the other side in the axial direction of the coil bobbin around which the coil is wound, and the outer peripheral side magnetic pole portion (teeth portion) of the first yoke is arranged. A claw pole type is known in which the first yoke and the second yoke are assembled to the coil bobbin so that the magnetic pole portions (teeth portions) on the outer peripheral side of the second yoke are alternately arranged in the circumferential direction.

For example, in the hub dynamo described in Patent Document 1, each yoke of the first yoke and the second yoke is a laminated yoke in which a plurality of flat plate-shaped members made of magnetic materials are laminated in a direction orthogonal to the radial direction of the coil. It is configured and each has a U-shaped side view.
That is, the first yoke is located on the outer peripheral side of the coil and has an outer peripheral magnetic pole portion whose tip extends from one end side in the axial direction of the coil to the other end side in the axial direction, and the shaft of the coil is located on the inner peripheral side of the coil. The inner peripheral side magnetic pole portion whose tip extends from one end side in the direction to the intermediate position toward the other end side in the axial direction, and the outer peripheral side magnetic pole portion and the inner side which extend linearly along the radial direction on one end side in the axial direction of the coil. It has a U-shaped side view with a connecting portion that connects the base ends of the peripheral magnetic pole portions.

The second yoke is located on the outer peripheral side of the coil and has a magnetic pole portion on the outer peripheral side whose tip extends from the other end side in the axial direction to the one end side in the axial direction, and the shaft of the coil located on the inner peripheral side of the coil. The inner peripheral side magnetic pole portion whose tip extends from the other end side in the direction to the intermediate position toward the one end side in the axial direction, and the outer peripheral side magnetic pole portion extending linearly along the radial direction on the other end side in the axial direction of the coil. It has a U-shaped side view having a connecting portion for connecting the base ends of the inner peripheral side magnetic pole portions.
Then, on the inner peripheral side of the coil, the tip of the inner peripheral side magnetic pole portion of the first yoke and the tip of the inner peripheral side magnetic pole portion of the second yoke are brought into contact with each other, whereby the first yoke and the second yoke are brought into contact with each other. It is magnetically connected.

By the way, the first yoke and the second yoke are arranged alternately in the circumferential direction and are arranged radially along the radial direction when viewed from the center of the coil. Therefore, the positions of the magnetic poles on the inner peripheral side of the adjacent first yoke and the second yoke are deviated in the circumferential direction. Therefore, even when the inner peripheral side magnetic pole portions of the first yoke and the second yoke are densely arranged in the circumferential direction, the tips of the inner peripheral side magnetic pole portions of one first yoke are adjacent to each other. It straddles the tip of the magnetic pole portion on the inner peripheral side of the two second yokes and comes into contact with each other. Similarly, the tips of the inner peripheral magnetic poles of one second yoke straddle the tips of the inner peripheral magnetic poles of the two adjacent first yokes and come into contact with each other. That is, the inner peripheral side magnetic pole portion of the first yoke and the inner peripheral side magnetic pole portion of the second yoke come into contact with each other in a one-to-two relationship.

Japanese Patent No. 5357937

When actually assembling the stator of the hub dynamo, the first yoke is inserted into the coil bobbin from one side in the axial direction, and the second yoke is inserted from the other side in the axial direction. At that time, for example, of the two inner peripheral magnetic poles of the second yoke to which the tips of the inner magnetic poles of the first yoke abut, the insertion direction dimension of the inner magnetic pole of one second yoke is the other. If it is shorter than the insertion direction dimension of the inner peripheral side magnetic pole portion of the second yoke (that is, if the insertion direction dimension of the inner peripheral side magnetic pole portion of the two adjacent second yokes varies), the following can occur. is there.

That is, the tip of the inner peripheral side magnetic pole portion of the first yoke abuts only on the tip of the inner peripheral side magnetic pole portion of one of the second yokes having a long insertion direction dimension, and the tip of the other second yoke inner peripheral side magnetic pole portion. There may be a gap between the tip of the inner peripheral side magnetic pole portion of the first yoke and the tip of the other inner peripheral side magnetic pole portion of the second yoke without contacting the magnet. As described above, if a gap is generated in the abutting portion between the yokes due to the variation of the contact surface due to the dimensional tolerance or the like, the iron loss of the yokes becomes large and the performance may deteriorate.

Therefore, the present invention has been made in view of the above-mentioned circumstances, and it is possible to absorb the dimensional variation of the yokes so that there is no gap between the abutting surfaces of the yokes, and the performance is improved. The purpose is to provide a hub dynamo that can be improved.

In order to solve the above problems, the hub dynamo according to the present invention rotatably supports a hub shell that rotates together with the wheels, a rotor having a permanent magnet arranged around the inner circumference of the body of the hub shell, and the wheels. It has a ring-shaped coil that is non-rotatably fixed to the hub shaft and is arranged on the inner peripheral side of the permanent magnet while being housed inside the hub shell and outputs an alternating current by the rotation of the rotor. In a hub dynamo including a stator, the stator is arranged as a stator core on one side in the axial direction and the other side in the axial direction so as to surround the ring-shaped coil, and is radially spaced apart in the circumferential direction. It has a plurality of first yokes and a plurality of second yokes arranged in the coil and alternately arranged in the circumferential direction, and the first yoke is located on the outer peripheral side of the coil and is one end side in the axial direction of the coil. The tip is extended from the outer peripheral side magnetic pole portion whose tip is extended to the other end side in the axial direction and the intermediate position located on the inner peripheral side of the coil from one end side in the axial direction to the other end side in the axial direction. It has an inner peripheral side magnetic pole portion and a connecting portion that extends linearly on one end side in the axial direction of the coil and connects the outer peripheral side magnetic pole portion and the base ends of the inner peripheral side magnetic pole portion. The two yokes are located on the outer peripheral side of the coil and have an outer peripheral magnetic pole portion whose tip extends from the other end side in the axial direction to the one end side in the axial direction of the coil, and the inner peripheral side of the coil. The inner peripheral side magnetic pole portion whose tip extends from the other end side in the axial direction to the intermediate position toward the one end side in the axial direction, and the outer peripheral side magnetic pole portion and the inner side which extend linearly on the other end side in the axial direction of the coil. The first yoke and the second yoke are configured as a laminated yoke in which a plurality of flat plate-shaped members made of a magnetic material are laminated, and having a connecting portion for connecting the base ends of the peripheral magnetic pole portions. When arranging the first yoke and the second yoke, the arrangement position of the first yoke and the arrangement position of the second yoke are alternately set on the outer peripheral surface of the stator at intervals in the circumferential direction, and the hub A plane including the central axis of the shaft and the center in the circumferential direction of the outer peripheral surface side of the outer peripheral side magnetic pole portion of the first yoke is set as the arrangement reference surface of the first yoke, and the arrangement reference surface of the first yoke. By setting a plane inclined to one side in the circumferential direction as the actual arrangement surface of the first yoke , the outer peripheral side magnetic pole portion of the first yoke is placed on the same surface of the actual arrangement surface of the first yoke. , The inner peripheral side magnetic pole portion, and the connecting portion are arranged , and the central axis of the hub shaft is arranged. A plane including the wire and the circumferential center of the outer peripheral surface side of the outer peripheral side magnetic pole portion of the second yoke is set as the arrangement reference surface of the second yoke, and with respect to the arrangement reference surface of the second yoke. By setting a plane inclined to the other side in the circumferential direction as the actual arrangement surface of the second yoke , the outer peripheral side magnetic pole portion of the second yoke is placed on the same surface of the actual arrangement surface of the second yoke . The peripheral magnetic pole portion and the connecting portion are arranged, and on the intersection line between the actual arrangement surface of the first yoke and the actual arrangement surface of the second yoke, with the tip of the inner peripheral side magnetic pole portion of the first yoke. It is characterized in that the tip of the inner peripheral side magnetic pole portion of the second yoke is in contact with the tip.

In this configuration, since the yoke is arranged not on the plane along the radial direction but on the plane inclined with respect to the radial direction (the actual arrangement surface of the yoke), it is the magnetic pole portion on the inner peripheral side of the first yoke. The magnetic poles on the inner peripheral side of the second yoke can be brought into contact with each other in a one-to-one relationship. Therefore, it is possible to eliminate the formation of a gap between the contact surfaces of the first yoke and the second yoke due to variations due to the dimensional tolerance of the yoke, and it is possible to improve the degree of adhesion of the contact surfaces. As a result, the magnetic connection of the yoke can be stabilized and iron loss can be reduced. In addition, since the first yoke and the second yoke can be connected in a one-to-one relationship, the first yoke and the first yoke can be adjusted downward from the 100% state to, for example, 75%, 50%, and 25%. It is sufficient to reduce the number of 2 yokes by the same number, and the required number of yokes can be reduced.

In the hub dynamo according to the present invention, the stator has a coil bobbin made of a non-magnetic material, and the coil bobbin is provided on a cylindrical body around which the coil is wound and on the outer periphery of both ends in the axial direction of the body. It has a first flange and a second flange provided, and the first yoke is actually arranged in the first yoke by engaging one end portion of the first yoke in the axial direction with the first flange. A guide portion for positioning on the surface is provided, and the second yoke is positioned on the actual arrangement surface of the second yoke by engaging the other end portion of the second yoke in the axial direction with the second flange. It is characterized in that a guide portion is provided.

In this configuration, the first yoke can be positioned on the actual arrangement surface of the first yoke by engaging the guide portion of the first flange of the coil bobbin with the axial end portion of the first yoke. Further, by engaging the axial end portion of the second yoke with the guide portion of the second flange of the coil bobbin, the second yoke can be positioned on the actual arrangement surface of the second yoke. Therefore, by assembling the first yoke and the second yoke to the coil bobbin, the positional relationship between the coil wound around the coil bobbin and the yoke can be appropriately determined.

In the hub dynamo according to the present invention, the guide portion is provided at the axial end portion of the first flange, and the connecting portion of the first yoke is fitted to fit the first yoke into the fruit of the first yoke. The second yoke is fitted with the second yoke by fitting the guide groove of the first yoke connecting portion positioned on the arrangement surface and the connecting portion of the second yoke provided at the axial end of the second flange. It is characterized by having a second yoke connecting portion guide groove for positioning on the actual arrangement surface of the above.

In this configuration, the yoke is properly positioned by fitting the connecting portion of each yoke into each of the first yoke connecting portion guide groove and the second yoke connecting portion guide groove provided at the axial end of the coil bobbin. However, it can be assembled to the coil bobbin.

In the hub dynamo according to the present invention, the guide portion is provided on the outer peripheral surface of the first flange, and the outer peripheral side magnetic pole portion of the first yoke is fitted to fit the first yoke into the actual first yoke. The second yoke is fitted with the second yoke by fitting the outer peripheral side guide groove of the first yoke positioned on the arrangement surface and the outer peripheral magnetic pole portion of the second yoke provided on the outer peripheral surface of the second flange. It is characterized by having a second yoke outer peripheral side guide groove for positioning on the actual arrangement surface of the magnet.

In this configuration, the yoke is properly positioned by fitting the outer peripheral side magnetic poles of each yoke into each of the first yoke outer peripheral side guide groove and the second yoke outer peripheral side guide groove provided on the outer peripheral surface of the coil bobbin. However, it can be assembled to the coil bobbin.

The hub dynamo according to the present invention has an inclination direction of the actual arrangement surface of the first yoke with respect to the arrangement reference surface of the first yoke and an inclination direction of the actual arrangement surface of the second yoke with respect to the arrangement reference surface of the second yoke. Is the inclination direction of each yoke, and the position of the radial outer peripheral end of the laminated plate-shaped members located on the rear side of the inclination direction of the first yoke and the second yoke is the position of the first yoke. The second yoke is characterized in that it projects radially outward with respect to the position of the radial outer peripheral end of the laminated plate-shaped member located on the front side in the inclination direction.

In this configuration, the gap (air) between the outer peripheral edge of the first yoke and the second yoke (the outer peripheral edge of the magnetic pole portion on the outer peripheral side of each yoke) in which a plurality of plate-shaped members are laminated and the inner peripheral surface of the permanent magnet. It can contribute to the uniformity of the gap).

That is, when the yoke is arranged so as to be inclined with respect to the radial direction, the laminated plate-like member is located on the rear side in the inclined direction of the yoke from the position of the radial outer peripheral end of the laminated plate-like member located on the front side in the inclined direction. The position of the outer peripheral end in the radial direction of the member is recessed inward in the radial direction. That is, the diameter of the laminated plate-shaped member at the position rearward in the tilting direction from the gap (air gap) between the radial outer peripheral end of the laminated plate-shaped member and the inner circumference of the permanent magnet at the position on the front side in the tilting direction. The gap (air gap) between the outer peripheral edge in the direction and the inner circumference of the permanent magnet becomes larger, and the air gap becomes biased.

Therefore, as described above, the radial direction of the laminated plate-shaped member located on the rear side in the inclined direction of the yoke with respect to the position of the radial outer peripheral end of the laminated plate-shaped member located on the front side in the inclined direction of each yoke. The position of the outer peripheral edge is projected outward in the radial direction. That is, the dimension of the outer peripheral edge of the yoke on the surface facing the permanent magnet is adjusted. By doing so, the gap (air gap) between the outer peripheral edge of each yoke and the inner peripheral surface of the permanent magnet can be made uniform, and as a result, the power generation efficiency can be improved.
The position of the radial outer peripheral end of the laminated plate-shaped member located on the rear side in the inclined direction of the yoke is set with respect to the position of the radial outer peripheral end of the laminated plate-shaped member located on the front side in the inclined direction of each yoke. As a method of projecting outward in the radial direction, the dimensions of the plate-shaped members laminated on the front side and the rear side in the inclination direction are different, or the stacking position of the plate-shaped members laminated on the front side and the rear side in the inclination direction. It is possible to adopt a method of shifting.

The hub dynamo according to the present invention refers to the other first yoke and the second yoke that are radially adjacent to at least one of the first yoke and the inner peripheral end of the second yoke on one end side or the other end side in the circumferential direction. It is characterized in that a notch portion is provided to avoid interference between the inner peripheral ends.

In this configuration, interference between the inner peripheral portions of adjacent yokes can be avoided, and the yokes can be densely arranged in the circumferential direction. That is, when the yokes are arranged radially, the number of yokes arranged may be limited due to the interference of the inner peripheral portions of the adjacent yokes. Therefore, the number of yokes to be arranged can be increased by providing the notch portion for avoiding interference as described above.

According to the hub dynamo according to the present invention, since the yoke is arranged not on the plane along the radial direction but on the plane inclined with respect to the radial direction (the actual arrangement surface of the yoke), the inside of the first yoke The peripheral magnetic pole portion and the inner peripheral side magnetic pole portion of the second yoke can be brought into contact with each other in a one-to-one relationship. Therefore, it is possible to eliminate the formation of a gap between the contact surfaces of the first yoke and the second yoke due to variations due to the dimensional tolerance of the yoke, and it is possible to increase the degree of adhesion of the contact surfaces. As a result, the magnetic connection of the yoke can be stabilized and iron loss can be reduced. In addition, since the first yoke and the second yoke can be connected in a one-to-one relationship, the first yoke and the second yoke can be adjusted downward from the 100% state to 75%, 50%, and 25%. It is only necessary to reduce the number of yokes by the same number, and the required number of yokes can be reduced, which can contribute to weight reduction and cost reduction.

It is the installation schematic drawing of the hub dynamo in embodiment of this invention. It is a side view of the hub dynamo in embodiment of this invention. It is sectional drawing of the hub dynamo in embodiment of this invention. It is a perspective view of the stator unit which comprises the hub dynamo in embodiment of this invention. It is a side view of the stator unit which comprises the hub dynamo in embodiment of this invention. It is a perspective view of the stator which constitutes the hub dynamo in embodiment of this invention. It is an exploded perspective view of the stator which constitutes the hub dynamo in embodiment of this invention. It is a perspective view of the coil bobbin of the stator which constitutes the hub dynamo in embodiment of this invention. It is a perspective view which shows the state which the coil is wound around the coil bobbin of the stator which constitutes the hub dynamo in embodiment of this invention. It is a perspective half sectional view of the stator which constitutes the hub dynamo in embodiment of this invention. It is a view seen from the axial direction of the stator which comprises the hub dynamo in embodiment of this invention, (a) is the EA arrow view of FIG. 6, and (b) is the EB arrow view of FIG. It is a figure of a set of yokes and a coil bobbin seen from the axial direction for demonstrating the arrangement angle of the 1st yoke and the 2nd yoke of the stator constituting the hub dynamo in embodiment of this invention. It is a figure for demonstrating the arrangement angle of the 1st yoke and the 2nd yoke of the stator constituting the hub dynamo in embodiment of this invention, (a) is the perspective which shows the state before combining the 1st yoke and the 2nd yoke. FIG. 3B is a perspective view showing a state after combining the first yoke and the second yoke, and FIG. 13C is a view taken along the line F of FIG. 13B. It is a figure for demonstrating the structure of each yoke of the stator which comprises the hub dynamo in embodiment of this invention, (a) is the perspective view of one plate-like member which constitutes a yoke, (b) is a plate-like member. (C) is a perspective view of the yoke as seen from the connecting portion side. It is a figure for demonstrating the problem of interference between adjacent yokes of the stator which constitutes a hub dynamo in embodiment of this invention. In the figure for demonstrating the problem of the air gap between the outer peripheral edge of each yoke of the stator which constitutes the hub dynamo in embodiment of this invention, and the inner peripheral surface of a permanent magnet, (a) is a figure in which the yoke is arranged diagonally. The figure for explaining the variation in the air gap due to the air gap, (b) shows a state in which the position of the outer peripheral edge of each plate-shaped member constituting the yoke is adjusted in order to make the air gap uniform. It is a figure. In the explanatory view of the effect of the hub dynamo in the embodiment of the present invention, (a) is the present embodiment in which a gap is not generated on the contact surface because the first yoke and the second yoke are in contact with each other in a one-to-one relationship. (B) is a diagram showing a comparative example showing that a gap may be generated in the contact surface due to the first yoke and the second yoke being in contact with each other in a one-to-two relationship. is there. It is explanatory drawing of the arrangement number of the yoke of the hub dynamo in embodiment of this invention, and is the figure which shows the state at the time of 100% output which all the 1st yoke and 2nd yoke are arranged. It is explanatory drawing of the arrangement number of the yoke of the hub dynamo in embodiment of this invention, and is the figure which shows the state at the time of 75% output which thinned out 25% of the 1st yoke and 2nd yoke. It is explanatory drawing of the arrangement number of the yoke of the hub dynamo in embodiment of this invention, and is the figure which shows the state at the time of 50% output which thinned out 50% of the 1st yoke and 2nd yoke. An explanatory diagram showing the effect of the hub dynamo in the embodiment of the present invention in comparison with a comparative example, (a) is a diagram showing the required number of yokes in the case of the embodiment at 50% output, and (b) is a 50% output. A diagram showing the required number of yokes in the case of the comparative example of time, (c) is a diagram showing the required number of yokes in the case of the embodiment at 25% output, and (d) is a diagram showing the required number of yokes in the case of the comparative example at 25% output. It is a figure which shows the required number of yokes of.

Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic mounting diagram of the hub dynamo 10. In the following description, a case where the hub dynamo 10 according to the present invention is attached to the hub shaft 11 of the bicycle 1 to supply electric power to the headlight 4 of the bicycle 1 will be described. In the headlight 4, an LED lamp is used as the lamp instead of the filament type light bulb.

(Hub dynamo mounting mode)
As shown in FIG. 1, the front wheel 5 of the bicycle 1 is rotatably supported via a hub shaft 11 by a front fork 3 forming a part of a frame. Both sides of the hub shaft 11 are fastened and fixed to the front fork 3 so as not to rotate by nuts (not shown) or the like. A hub dynamo 10 is attached coaxially with the hub shaft 11 to most of the center of the hub shaft 11 in the axial direction. The hub dynamo 10 is provided to supply electric power to the headlights 4 arranged on the side of the front wheel 5.

The hub dynamo 10 is connected to the spokes 2 of the front wheel 5 and rotates together with the front wheel 5 around the hub shaft 11 (described later), and the hub dynamo 10 cannot rotate to the hub shaft 11 while being located on the inner peripheral side of the rotor 20. It is provided with a stator 101 (described later) attached to the above.
Hereinafter, the axial direction of the central axis O of the hub axis 11 is simply referred to as an axial direction, the direction orthogonal to the axial direction is referred to as a radial direction, and the direction along the circumference of the central axis O is referred to as a circumferential direction. A male screw portion (not shown) for fixing the hub dynamo 10 to the front fork 3 is provided in a portion of the hub shaft 11 located at least axially outside the portion to which the stator 101 (described later) is attached. It is formed.

(Rotor)
FIG. 2 is a side view of the hub dynamo 10. FIG. 3 is a cross-sectional view of the hub dynamo 10.
As shown in FIGS. 2 and 3, the rotor 20 is mainly composed of the hub shell 30. The hub shell 30 includes a cylindrical body portion (cylindrical portion) 31 integrally molded into a substantially bottomed cylindrical shape, a second end plate 33 on the other Q side (right side in FIG. 3) in the axial direction of the body portion 31, and a body. It is composed of a first end plate 32 that closes an opening on the P side (left side in FIG. 3) of the portion 31 in the axial direction. The first end plate 32 is press-fitted and fixed to the body portion 31.

A flange portion 34 is formed on the outer periphery of the hub shell 30 on one P side in the axial direction and on the other Q side in the axial direction so as to project outward in the radial direction. A plurality of support holes 34a penetrating in the axial direction are formed in each flange portion 34 at equal intervals in the circumferential direction. As shown in FIG. 1, the support holes 34a are engaged with the inner ends of a plurality of spokes 2 extending from the rim 5a of the front wheel 5 to the inner diameter side. The support holes 34a of the left and right flange portions 34 are arranged so as to be out of phase in the circumferential direction by a half pitch.

The outer rings of bearings 35 and 36 are fitted to the inner circumferences of the first end plate 32 and the second end plate 33, respectively. The rotor 20 mainly composed of the hub shell 30 is rotatably supported by the hub shaft 11 via the bearings 35 and 36, so that the rotor 20 rotates about the hub shaft 11 together with the rotation of the front wheels 5. ing. That is, the rotor 20 functions as a hub that rotatably supports the front wheels 5.

A permanent magnet 22 formed of, for example, ferrite or the like is arranged on the inner circumference of the body 31 of the hub shell 30 via a cylindrical ring yoke 21. The ring yoke 21 is made of a magnetic metal material (for example, iron). By making the ring yoke 21 made of iron, for example, the hub shell 30 can be made of aluminum to reduce the weight. The permanent magnet 22 is arranged in close contact with the inner circumference of the ring yoke 21, and is attached by an adhesive or the like. By arranging the permanent magnets 22 in a cylindrical shape along the inner peripheral surface of the body portion 31, the permanent magnets 22 cover the entire outer peripheral surface of the stator 101.

The permanent magnet 22 is incorporated in the inner circumference of the body 31 of the hub shell 30 in a state of being divided into a plurality of pieces in the circumferential direction. On the inner peripheral surface of the permanent magnets 22 arranged in a cylindrical shape, the magnetic poles of the N pole and the S pole are alternately magnetized along the circumferential direction at equal intervals, and the first yoke 120A and the second yoke 120A and the second yoke described later are alternately magnetized. It faces the outer peripheral portion of the yoke 120B.

A large-diameter portion is formed in the axially intermediate portion of the hub shaft 11, and a stator 101 is attached to the outer periphery of the large-diameter portion. As shown in FIGS. 3 to 5, the stator 101 is positioned and fixed to the hub shaft 11 by a sleeve nut 42 and a tightening nut 44 via plate members 41 and 43 arranged at both ends in the axial direction thereof. The stator unit 100 is composed of the hub shaft 11 and the stator 101.

The inner ring of one bearing 35 is fitted to the outer circumference of the sleeve nut 42 arranged on one P side in the axial direction of the stator unit 100. A connector 50 is provided on the axially outer side of the bearing 35, and a nut 51 is arranged on the axially outer side of the connector 50. By screwing the nut 51 into the hub shaft 11, the connector 50 is fixed to the hub shaft 11, and one end side of the hub shell 30 is rotatably supported by the hub shaft 11 via the bearing 35.

Further, another sleeve nut 45 is arranged on the other Q side of the hub shaft 11 in the axial direction, and an inner ring of the other bearing 36 is fitted on the outer circumference of the sleeve nut 45. A cover 46 is provided on the outer side in the axial direction from the bearing 36, and a nut 47 is arranged on the inner peripheral portion of the cover 46. By screwing the nut 47 into the hub shaft 11, the cover 46 is fixed to the hub shaft 11, and the other end side of the hub shell 30 is rotatably supported by the hub shaft 11 via the bearing 36.

(Stator)
Next, the details of the stator 101 will be described.
FIG. 6 is a perspective view showing the configuration of the stator 101. FIG. 7 is an exploded perspective view showing the configuration of the stator 101.
As shown in FIGS. 6 and 7, the stator 101 includes a tubular coil bobbin 110 made of synthetic resin (made of a non-magnetic material) through which the hub shaft 11 is inserted, and a ring-shaped coil 140 wound around the coil bobbin 110. It is composed of a claw pole type stator core 120 assembled so as to surround the coil 140 inside. The hub shaft 11, the coil bobbin 110, the first yoke 120A, and the second yoke 120B are arranged coaxially.

Here, as elements constituting the claw pole type stator core 120, a plurality of first yokes 120A are arranged on one side P side in the axial direction, and a plurality of second yokes 120B are arranged on the other side Q side in the axial direction. .. The plurality of first yokes 120A and the plurality of second yokes 120B are arranged radially at regular intervals in the circumferential direction and are arranged so as to be alternately arranged in the circumferential direction. The outer peripheral portions of the yokes 120A and 120B are configured to face the inner peripheral surface 22a (see FIG. 3) of the permanent magnet 22 with a slight gap (air gap).

The number (number of poles) of the yokes 120A and 120B is set in relation to the number of magnetic poles of the permanent magnet 22. In the present embodiment, 16 first yokes 120A and 16 second yokes 120B are provided at regular intervals, for a total of 32 pieces. Although not shown, wiring is connected to the coil 140, and the wiring is drawn out along the hub shaft 11.

(Coil bobbin)
FIG. 8 is a perspective view of the coil bobbin. FIG. 9 is a perspective view showing a state in which the coil is wound around the coil bobbin.
As shown in FIGS. 8 and 9, the coil bobbin 110 has a cylindrical body portion 111 in which the coil 140 is wound around the outer circumference, and an outer peripheral portion of the end portion of the body portion 111 on one P side in the axial direction and the other Q side in the axial direction. It has a first flange 112A and a second flange 112B provided so as to project outward in the radial direction.

A guide groove 113A is provided on the axially outer end surface of the first flange 112A. On the outer peripheral surface of the first flange 112A, an engagement groove 114A communicating with the guide groove 113A is provided at a position corresponding to the guide groove 113A. The guide groove 113A and the engagement groove 114A are for positioning and attaching the first yoke 120A to the coil bobbin 110.
Further, a guide groove 113B is provided on the axially outer end surface of the second flange 112B. On the outer peripheral surface of the second flange 112B, an engaging groove 114B communicating with the guide groove 113B is provided at a position corresponding to the guide groove 113B. The guide groove 113B and the engagement groove 114B are for positioning and attaching the second yoke 120B to the coil bobbin 110.

Further, the outer peripheral surface of the first flange 112A and the outer peripheral surface of the second flange 112B are positioned in the middle of the circumferential directions of the engaging grooves 114A and 114B, respectively, and the second yoke 120B and the first yoke 120A on the other side are positioned in the middle. Support grooves 115A and 115B are provided to support the tip of the. That is, since the first yoke 120A and the second yoke 120B are alternately arranged at regular intervals in the circumferential direction, the position of the engagement groove 114A of the first flange 112A in the circumferential direction and the support groove 115B of the second flange 112B The positions in the circumferential direction match, and the positions in the circumferential direction of the engagement groove 114B of the second flange 112B and the positions in the circumferential direction of the support groove 115A of the first flange 112A match. Details of the guide grooves 113A and 113B, the engaging grooves 114A and 114B, and the support grooves 115A and 115B will be described later.

(yoke)
10 is a perspective half-sectional view of the stator, FIG. 11 is a view seen from the axial direction of the stator, FIG. 10A is an arrow view of EA of FIG. 6, and FIG. 11B is an arrow view of EB of FIG. It is a figure. FIG. 12 is a view of a set of yokes and coil bobbins viewed from the axial direction for explaining the arrangement angles of the first yoke and the second yoke of the stator. 13A and 13B are views for explaining the arrangement angle of the first yoke and the second yoke. FIG. 13A is a perspective view showing a state before combining the first yoke and the second yoke, and FIG. 13B is a perspective view showing a state before combining the first yoke and the second yoke. A perspective view showing a state after the combination of the 1-yoke and the 2nd yoke, (c) is a view taken along the line F of FIG. 13 (b). 14A and 14B are views for explaining the configuration of each yoke. FIG. 14A is a perspective view of one plate-shaped member constituting the yoke, and FIG. 14B is a yoke configured by laminating the plate-shaped members. (C) is a perspective view of the yoke as seen from the connecting portion side.

The first yoke 120A and the second yoke 120B are assembled to the coil bobbin 110 as shown in FIGS. 13 (a) to 13 (c) with an example of a combination of the first yoke 120A and the second yoke 120B. It has the same structure, only in the opposite direction, and has a U-shaped side view.

That is, as shown in FIGS. 13 (a) to 13 (c) and FIG. 7, the first yoke 120A is located on the outer peripheral side of the coil 140 and is axially oriented from one end side (P side) in the axial direction of the coil 140. The outer peripheral side magnetic pole portion 121 whose tip is extended to the other end side (Q side) and the axial end side (Q side) of the coil 140 located on the inner peripheral side of the coil 140 from the axial end side (P side). The inner peripheral side magnetic pole portion 123 having the tip 123a extended to the intermediate position toward the coil 140, and the outer peripheral side magnetic pole portion 121 and the inner circumference extending linearly along the radial direction on one end side (P side) in the axial direction of the coil 140. It has a connecting portion 122 that connects the base ends of the side magnetic pole portions 123 to each other.

Similarly, the second yoke 120B is located on the outer peripheral side of the coil 140 and has an outer peripheral side magnetic pole portion 121 having a tip extending from the other end side (Q side) in the axial direction of the coil 140 to one end side (P side) in the axial direction. , The inner peripheral side magnetic pole portion 123 located on the inner peripheral side of the coil 140 and extending the tip from the other end side (Q side) in the axial direction of the coil 140 to the intermediate position toward the one end side (P side) in the axial direction. On the other end side (Q side) of the coil 140 in the axial direction, there is a connecting portion 122 extending linearly along the radial direction and connecting the base ends of the outer peripheral side magnetic pole portion 121 and the inner peripheral side magnetic pole portion 123. doing.

The radial outer peripheral edge of the outer peripheral side magnetic pole portion 121 is arranged substantially parallel to the hub shaft 11. The outer peripheral side magnetic pole portion 121 is formed in a tapered shape so that the inner peripheral edge in the radial direction approaches the outer peripheral edge in the radial direction toward the tip. At the tip of the outer peripheral magnetic pole portion 121, the radial inner peripheral edge and the radial outer peripheral edge are parallel to each other. That is, the radial inner peripheral edge of the outer peripheral side magnetic pole portion 121 is formed obliquely from the base end to the tip end, and is formed parallel to the radial outer peripheral edge at the tip end portion. The radial inner peripheral edge and the radial outer peripheral edge of the inner peripheral side magnetic pole portion 123 are formed in parallel with the outer peripheral edge of the outer peripheral side magnetic pole portion 121.

As shown in FIG. 10, the inner peripheral magnetic pole portions 123 of the yokes 120A and 120B are inserted into the inner circumference of the coil bobbin 110 so as to be located on the inner peripheral side of the coil 140, and the inner circumference of the body portion 111 of the coil bobbin 110 It is located between the surface and the outer peripheral surface of the hub shaft 11. The hub shaft 11 is fixed through the stator center hole 150 (see FIG. 11) surrounded by the inner peripheral side magnetic pole portions 123 of the yokes 120A and 120B densely arranged in the circumferential direction (see FIG. 4).

(Plate-shaped member)
Here, as shown in FIGS. 14 (a) to 14 (c), each of the first yoke 120A and the second yoke 120B has a plurality of flat plate-shaped members 130 made of a magnetic material such as iron in a plate thickness. It is configured as a laminated yoke (laminated body) laminated in a direction (a direction orthogonal to the radial direction of the coil 140). As a material for the plate-shaped member 130 (also referred to as a laminated plate-shaped member), for example, a silicon steel plate having an oxide film formed on its surface (more specifically, a non-directional silicon steel plate) is used. These plate-shaped members 130 are formed by punching out a plate material by a press or the like, and are not bent when forming the yokes 120A and 120B, and are configured as a flat plate body.

As shown in FIG. 14A, each plate-shaped member 130 is a substantially U-shaped iron piece, and the outer peripheral side magnetic pole portion 131 and the inner peripheral side magnetic pole portion 133 forming the corresponding two sides, and the inner peripheral side magnetic pole portion 133, and the respective plate-shaped member 130 It has a connecting portion 132 which is one side to be connected.
The basic shape of each plate-shaped member 130 is the same, and as shown in FIGS. 14 (b) and 14 (c), a predetermined number of plate-shaped members 130 are laminated in the plate thickness direction to form a plate. The outer peripheral side magnetic poles 131 of the shaped member 130 constitute the outer peripheral side magnetic poles 121 of the yokes 120A and 120B. Further, the inner peripheral side magnetic pole portions 133 of the plate-shaped member 130 constitute the inner peripheral side magnetic pole portions 123 of the yokes 120A and 120B. Further, the connecting portion 132 of the plate-shaped member 130 constitutes the connecting portion 122 of the yokes 120A and 120B. In this example, the yokes 120A and 120B are formed by laminating seven plate-shaped members 130.

As shown in FIG. 7, the first yokes 120A and 120B are radially assembled to the coil bobbin 110 so that the outer peripheral side magnetic pole portion 121 is on the outer diameter side when viewed from the axial direction. The first yoke 120A and the second yoke 120B are arranged so as to be alternately arranged at a constant interval in the circumferential direction (in this example, the central angle = 360 ° / 32).

What is important here is that, as shown in FIGS. 11 to 13, the yokes 120A and 120B are not simply arranged on a plane along the radial direction, but on a plane inclined with respect to the radial direction. It is arranged on the actual arrangement surface of the yoke described later).

As described above, the first yoke 120A and the second yoke 120B are arranged alternately in the circumferential direction and radially when viewed from the center of the coil 140. Therefore, if the first yoke 120A and the second yoke 120B are simply arranged on a plane along the radial direction, the positions of the magnetic pole portions 123 on the inner peripheral side of the adjacent first yoke 120A and the second yoke 120B are circular. It will shift in the circumferential direction. Then, the inner peripheral side magnetic pole portions 123 of the adjacent first yoke 120A and the second yoke 120B cannot be magnetically connected on a one-to-one basis.

Therefore, the first yoke 120A and the second yoke 120B are arranged on a plane inclined with respect to the radial direction. That is, as shown in FIGS. 11A, 11B, and 12, first, when the yokes 120A and 120B are arranged, they are spaced apart from each other in the circumferential direction on the outer peripheral surface of the stator 101 (θ = 11.25). ° = 360 ° / 32), the arrangement position QA of the first yoke and the arrangement position QB of the second yoke are alternately set.

Next, as shown in FIGS. 11A and 12, the central axis O of the hub shaft and the circumferential center QA of the outer peripheral surface of the outer peripheral magnetic pole portion 121 of the first yoke 120A (hereinafter, the arrangement of the first yoke). The plane containing (referred to as position QA) and is set as the placement reference plane SA0 of the first yoke. In addition to this, a plane including the arrangement position QA of the first yoke, parallel to the central axis O of the hub axis, and inclined by an angle αA to one side RA in the circumferential direction with respect to the arrangement reference surface SA0 of the first yoke is the first. It is set as the actual arrangement surface SA1 of 1 yoke. Then, the first yoke 120A is arranged on the actual arrangement surface SA1 of the first yoke.

Further, as shown in FIGS. 11B and 12, the central axis O of the hub shaft and the circumferential center QB of the outer peripheral surface of the outer peripheral magnetic pole portion 121 of the second yoke 120B (hereinafter, the arrangement position of the second yoke). A plane containing (QB) and is set as the arrangement reference plane SB0 of the second yoke. In addition to this, a plane including the arrangement position QB of the second yoke, parallel to the central axis O of the hub axis, and inclined by an angle αB to the other side RB in the circumferential direction with respect to the arrangement reference surface SB0 of the second yoke is the second. 2 It is set as the actual arrangement surface SB1 of the yoke. Then, the second yoke 120B is arranged on the actual arrangement surface SB1 of the second yoke.

In this case, since the distance between the arrangement position QA of the adjacent first yoke 120A and the arrangement position QB of the second yoke 120B is θ = 11.25 ° (= 360 ° / 32), the actual arrangement surface of the first yoke The inclination angles αA and αB of the actual placement surfaces SB1 of the SA1 and the second yoke with respect to the placement reference surfaces SA0 and SB0 are smaller than αA = αB = 5.625 ° (= 11.25 ° / 2), for example, 5. It is set to °.

Then, on the intersection line SC (see FIG. 12) between the actual arrangement surface SA1 of the first yoke and the actual arrangement surface SB1 of the second yoke, by combining them as shown by the arrows FP and FQ in FIG. 13A, FIG. As shown in 13 (b) and 13 (c), the tip 123a of the inner peripheral side magnetic pole portion 123 of the first yoke 120A and the tip 123a of the inner peripheral side magnetic pole portion 123 of the second yoke 120B are brought into contact with each other. There is. As a result, the inner peripheral side magnetic pole portion 123 of the first yoke 120A and the inner peripheral side magnetic pole portion 123 of the second yoke 120B are magnetically connected in a one-to-one relationship.

As described above, the following can be said from the relationship that the yokes 120A and 120B are arranged on a plane inclined with respect to the radial direction (actual arrangement surfaces SA1 and SB1 of the yokes).
That is, as shown in FIGS. 11 and 12, the guide grooves 113A and 113B of the first flange 112A and the second flange 112B of the coil bobbin 110 also have the same inclination angle αA with respect to the radial direction. It is formed to have αB.

Further, the engaging grooves 114A and 114B are formed so as to follow the inclination of the guide grooves 113A and 113B. Regarding the support grooves 115A and 115B that accommodate and support the tips of the outer peripheral magnetic poles 121 of the mating yokes 120A and 120B, some of the support grooves 115A and 115B are slightly positioned so as to give priority to the dimensional accuracy of the engagement grooves 114B and 114A whose positions correspond in the circumferential direction. It is formed with a margin.

At the time of assembly, as shown in FIG. 7, the first yoke 120A and the second yoke 120B are alternately inserted into the coil bobbin 110 from one P side in the axial direction and the other Q side in the axial direction. That is, the connecting portions 122 of the yokes 120A and 120B are fitted into the guide grooves 113A and 113B of the first flange 112A and the second flange 112B of the coil bobbin 110. Further, the base ends of the outer peripheral magnetic pole portions 121 of the yokes 120A and 120B are fitted into the engaging grooves 114A and 114B of the first flange 112A and the second flange 112B of the coil bobbin 110.

Further, the tips of the outer peripheral magnetic poles 121 of the yokes 120A and 120B are accommodated in the engaging grooves 114A and 114B of the second flange 112B and the first flange 112A on the opposite side of the coil bobbin 110. Further, the inner peripheral side magnetic pole portions 123 of the yokes 120A and 120B are inserted along the inner peripheral surface of the coil bobbin 110, and the tips of the inner peripheral side magnetic pole portions 123 of the respective yokes 120A and 120B are brought into contact with each other. As a result, the yokes 120A and 120B are mounted so as to surround the coil 140.

By assembling as described above, the outer peripheral side magnetic pole portion 121 of the first yoke 120A and the outer peripheral side magnetic pole portion 121 of the second yoke 120B are connected to the ring-shaped coil 140 wound around the body portion 111 of the coil bobbin 110. On the outer peripheral side, they are alternately arranged at intervals in the circumferential direction. Further, the inner peripheral side magnetic pole portion 123 of the first yoke 120A and the inner peripheral side magnetic pole portion 123 of the second yoke 120B are arranged on the inner peripheral side of the ring-shaped coil 140 wound around the body of the coil bobbin 110. Magnet.

At that time, the guide groove 113A of the first flange 112A of the coil bobbin 110 serves to position the first yoke 120A on the actual arrangement surface SA1 of the first yoke. Further, the guide groove 113B of the second flange 112B serves to position the second yoke 120B on the actual arrangement surface SB1 of the second yoke. The plurality of yokes 120A and 120B are held so as not to rotate with respect to the coil bobbin 110.

Next, the details of the yokes 120A and 120B will be described.
FIG. 15 is a diagram for explaining the problem of interference between adjacent yokes. FIG. 16 is a diagram for explaining the problem of the air gap between the outer peripheral edge of each yoke and the inner peripheral surface of the permanent magnet, and FIG. 16A is a diagram showing variations in the air gap due to the oblique arrangement of the yokes. (B) is a diagram for explaining the occurrence of the above, and is a diagram showing a state in which the position of the outer peripheral edge of each plate-shaped member constituting the yoke is adjusted in order to make the air gap uniform.

(Avoiding interference at the inner peripheral ends of adjacent yokes)
As shown in FIG. 15, when the yokes 120A and 120B are arranged radially when viewed from the axial direction at intervals in the circumferential direction, the inner peripheral side magnetic pole portions 123 of the adjacent yokes 120A are densely arranged, and they are closely aligned with each other. There is a possibility of interference. Therefore, in the present embodiment, a notch 135 for avoiding interference between the inner peripheral ends of the adjacent yokes 120A is provided at least on one end side or the other end side in the circumferential direction of the inner peripheral side magnetic pole portion 123. The same applies to the other yoke 120B.

Here, the inclination direction of the actual arrangement surface SA1 of the first yoke with respect to the arrangement reference surface SA0 of the first yoke 120A and the inclination direction of the actual arrangement surface SB1 of the second yoke with respect to the arrangement reference surface SB0 of the second yoke 120B are shown. Defined as the direction of inclination of the yoke. Further, the seven stacked plate-shaped members 130 will be indicated by reference numerals 130-1 to 130-7, which are distinguished from the front side to the rear side in the inclination direction.
In such a case, the position of the radial inner peripheral end of the laminated plate-like member (for example, plate-like member 130-1) located on the front side in the inclination direction of the yoke 120A (120B) is in the inclination direction of the yoke 120A (120B). The dimensions of the laminated plate-shaped member 130 are determined so as to be radially outward from the position of the radial inner peripheral end of the laminated plate-shaped member (for example, the plate-shaped member 130-7) located on the rear side. ing.

That is, as shown in FIG. 14C, the radial dimension K1 of the plate-shaped member 130-1 located at the front end in the inclination direction of the first yoke 120A (120B) is next to the plate-shaped member 130-1. The dimension K3 is set smaller than the radial dimension K2 of the plate-shaped member 130-2 located on the front side. Further, the radial dimension K2 of the plate-shaped member 130-2 is a dimension K5 more than the radial dimension K4 of the plate-shaped members 130-3 to 130-7 located behind the plate-shaped member 130-2 in the inclination direction. Is set small.
As a result, when the plate-shaped members 130-1 to 130-7 are laminated, the adjacent yoke 120A (120B) is placed at the front end in the inclined direction of the inner peripheral end of the inner peripheral side magnetic pole portion 123 of the yoke 120A (120B). A notch 135 is secured to avoid interference with the inner peripheral end of the inner magnetic pole portion 123.

Depending on the degree of possibility of interference, the radial dimensions of the plate-shaped members 130-2 to 130-7 are set to be the same, and the radial dimensions of the plate-shaped member 130-1 located at the foremost end in the inclined direction are set. Only K1 may be set shorter than the radial dimensions of the other plate-shaped members 130-2 to 130-7. Further, for example, the radial dimensions of the plate-shaped members 130-1 to the third plate-shaped members 130-3 and later in the tilting direction are also the plate-shaped members 130-3 to 130-7 located rearward in the tilting direction. The radial dimension may be set to be longer.

In this way, by providing the notch 135 at the inner peripheral end of the yoke 120A (120B) on the front side in the inclined direction, interference is avoided even if the distance between the plurality of yokes 120A (120B) arranged in the circumferential direction is close. You will be able to do it. In other words, a large number of yokes 120A (120B) can be arranged by reducing the arrangement interval of the yokes 120A (120B).

(Avoiding problems with the outer peripheral edge of the yoke)
Next, the problem of the outer peripheral end of each yoke 120A and 120B will be described.
As described above, when the yokes 120A and 120B are arranged so as to be inclined with respect to the radial direction, as shown in FIG. 16A, the laminated plate-like member (for example, the plate-like member 130) located on the front side in the inclination direction is arranged. The diameter of the radial outer peripheral end of the laminated plate-shaped member (for example, plate-shaped member 130-7) located behind the yokes 120A and 120B in the inclined direction is larger than the position of the radial outer peripheral end of -1). It becomes a shape that is retracted inward in the direction. That is, the gap (air gap) d1 between the radial outer peripheral end of the laminated plate-shaped member (for example, the plate-shaped member 130-1 at the front end) and the inner peripheral surface 22a of the permanent magnet 22 at the position on the front side in the inclination direction. A gap (air gap) between the radial outer peripheral end of the laminated plate-shaped member (for example, the plate-shaped member 130-7 at the rear end) and the inner peripheral surface 22a of the permanent magnet 22 at a position on the rear side in the inclined direction. d7 is larger. As a result, the air gaps d1 to d7 are biased. Actually, the gaps (air gaps) d1 to d7 between the outer peripheral end of each plate-shaped member 130-1 to 130-7 and the inner peripheral surface 22a of the permanent magnet 22 are d1 <d2 <d3 <d4 <d5. <D6 <d7.

Therefore, in the present embodiment, as shown in FIG. 16B, the radial outer peripheral end of the laminated plate-shaped member (for example, the plate-shaped member 130-1) located on the front side in the inclination direction of the yokes 120A and 120B. The position of the radial outer peripheral end of the laminated plate-shaped member (for example, the plate-shaped member 130-7) located on the rear side in the inclination direction of the yokes 120A and 120B protrudes outward from the position of. Is set to. Specifically, the laminated plate-like member 130- located at the front end in the inclination direction of the yokes 120A and 120B so as to project the outer peripheral edge of the outer peripheral magnetic pole portions 121 of the yokes 120A and 120B toward the outer diameter side. From the minimum value m1 of 1 to the maximum value m2 of the laminated plate-shaped members 130-7 located at the rear ends of the yokes 120A and 120B in the inclination direction, the values are gradually changed according to the stacking order. By doing so, the gaps (air gaps) d1 to d7 between the outer peripheral edges of the yokes 120A and 120B and the inner circumferences of the permanent magnets 22 can be made uniform.

The laminated plate-shaped members located on the rear side of the yokes 120A and 120B in the inclined direction from the positions of the radial outer peripheral ends of the laminated plate-shaped members 130 located on the front side in the inclined direction of the yokes 120A and 120B. The following method can also be adopted as a method of projecting the position of the outer peripheral end in the radial direction outward in the radial direction. That is, a method is adopted in which the dimensions of the plate-shaped members 130 laminated on the front side and the rear side in the inclination direction are different, or the stacking positions of the plate-shaped members 130 laminated on the front side and the rear side in the inclination direction are shifted. be able to.

Next, the action will be described.
(Mechanism of power generation)
The power generation of the hub dynamo 10 configured in this way is performed as follows.
That is, when the front wheel 5 rotates, the rotor 20 connected to the front wheel 5 by the spokes 2 rotates around the hub shaft 11 together with the front wheel 5, and the permanent magnet 22 rotates around the stator 101.

Due to the magnetic flux of the rotating permanent magnet 22, the outer peripheral side magnetic pole portion 121 of the first yoke 120A on the one P side in the axial direction becomes the N pole, and the outer peripheral side magnetic pole portion 121 of the second yoke 120B on the other Q side in the axial direction becomes the S pole. The state and the state in which the outer peripheral magnetic flux portion 121 of the first yoke 120A on the one P side in the axial direction is the S pole and the outer peripheral magnetic flux portion 121 of the second yoke 120B on the other Q side in the axial direction is the N pole alternately. Repeated. As a result, an alternating magnetic flux is generated in the inner peripheral side magnetic pole portions 123 of both yokes 120A and 120B that magnetically connect the two. Due to the alternating magnetic flux generated on the inner peripheral side of the coil, a current flows through the coil 140 of the stator 101 to generate electricity.

During this power generation, an eddy current is also generated in addition to the alternating magnetic flux. This eddy current lowers the power generation efficiency, but in the hub dynamo 10, since the yokes 120A and 120B are configured as a laminated body of a plurality of plate-shaped members 130, the generation of eddy current is suppressed. Can be done.

In the hub dynamo of the present embodiment, the first yoke 120A and the second yoke 120B are not on a plane along the radial direction (yoke arrangement reference planes SA0 and SB0), but on a plane inclined with respect to the radial direction (yoke). It is arranged on the actual arrangement surface SA1, SAB1). Therefore, the inner peripheral side magnetic pole portion 123 of the first yoke 120A and the inner peripheral side magnetic pole portion 123 of the second yoke 120B can be brought into contact with each other in a one-to-one relationship.

Therefore, as shown schematically in FIG. 17 (a), due to variations due to dimensional tolerances of the yokes 120A and 120B, the contact surfaces of the first yoke 120A and the second yoke 120B are shown in FIG. 17 (b). It is possible to eliminate the occurrence of a large gap G, and it is possible to increase the degree of adhesion of the contact surface. As a result, the magnetic connection between the yokes 120A and 120B can be stabilized, iron loss can be reduced, and efficiency can be improved.

Further, when the output is adjusted downward from the 100% output state shown in FIG. 18 using all of the 32-pole yokes 120A and 120B, the first yoke 120A and the second yoke 120B can be connected one-to-one. Therefore, the required number can be reduced. For example, when the output is reduced to 75% from the 100% output state shown in FIG. 18, the number of yokes 120A and 120B may be simply reduced to 3/4 as shown in FIG. Further, when the output is reduced to 50%, as shown in FIG. 20, the number of yokes 120A and 120B used may be simply reduced to 1/2.

Incidentally, in the case of the embodiment, since the connection between the first yoke 120A and the second yoke 120B can be made in a one-to-one relationship, when adjusting the output downward from the 100% state to, for example, 50% and 25%, the figure is shown. As shown in 21 (a) and 21 (c), the number of the first yoke 120A and the second yoke 120B may be reduced by the same number, and the required number of yokes 120A and 120B can be reduced. On the other hand, in the case of the comparative example (example of the conventional publication), even if the output is 50%, one yoke (for example, the second yoke 120B) must be used in full, and the output is 25%. However, I have no choice but to use half of both yokes 120A and 120B. In this way, the required number of yokes can be reduced when adjusting the output, which is advantageous in terms of cost and weight.

Further, in the present embodiment, by engaging the axial ends of the yokes 120A and 120B with the guide grooves 113A and 113B and the engaging grooves 114A and 114B of the flanges 112A and 112B of the coil bobbin 110, the yoke is inclined with respect to the radial direction. It can be positioned on an inclined flat surface (actual arrangement surface SA1 and SB1 of the yoke). Therefore, by assembling the yokes 120A and 120B to the coil bobbin 110, the positional relationship between the coil 140 wound around the coil bobbin 110 and the yokes 120A and 120B can be appropriately determined.

Further, in the present embodiment, even when the laminated yokes (first yoke 120A and second yoke 120B) are arranged so as to be inclined with respect to the radial direction, the outer peripheral edges of the yokes 120A and 120B (outer peripheral magnetic pole portions 121 of each yoke) are arranged. It can contribute to the equalization of the gap (air gap) between the outer peripheral edge of the magnet 22 and the inner peripheral surface 22a of the permanent magnet 22. As a result, the power generation efficiency can be improved.

Further, in the present embodiment, at least one of the inner peripheral ends of the yokes 120A and 120B on one end side or the other end side in the circumferential direction is provided with a notch 135 for avoiding interference between the inner peripheral ends of adjacent yokes. .. Therefore, it is possible to avoid interference between the inner peripheral portions of the adjacent yokes 120A and 120B, and the yokes 120A and 120B can be densely arranged in the circumferential direction. Therefore, the number of yokes arranged can be increased.

The present invention is not limited to the above-described embodiment, and includes various modifications of the above-described embodiment without departing from the spirit of the present invention.
For example, the number of stacked plate-shaped members 130 when forming the yokes 120A and 120B may be arbitrarily determined, and the number of yokes 120A and 120B at 100% output is not limited to 32. Further, the number of stators 101 is not limited to one, and two or three may be arranged on the hub shaft 11.

Further, in the above-described embodiment, the case where the stator unit 100 is composed of one stator 101 has been described. However, the present invention is not limited to this, and the stator unit 100 may be formed by arranging two or more stators 101 side by side on the hub shaft 11. In this case, by shifting the phases of the two stators 101, it is possible to generate an alternating current that is out of phase.

4 ... Headlight (light emitting diode)
5 ... Front wheels (wheels)
10 ... Hub dynamo 11 ... Hub shaft 20 ... Rotor 22 ... Permanent magnet 30 ... Hub shell 31 ... Body 101 ... Stator 110 ... Coil bobbin 111 ... Body 112A ... First flange 112B ... Second flange 113A ... Guide groove (first yoke) Connecting part guide groove)
113B ... Guide groove (guide groove at the second yoke connecting part)
114A ... Engagement groove (guide groove on the outer peripheral side of the first yoke)
114B ... Engagement groove (guide groove on the outer peripheral side of the second yoke)
120 ... Stator core 120A ... First yoke 120B ... Second yoke 121 ... Outer peripheral side magnetic pole portion 122 ... Connecting portion 123 ... Inner peripheral side magnetic pole portion 123a ... Tip 130, 130-1 to 130-7 ... Plate-shaped member 135 ... Notch 140 ... Coil QA ... Center in the circumferential direction (position of the first yoke)
QB: Center in the circumferential direction (position of the second yoke)
SA0 ... Placement reference surface of the first yoke SA1 ... Actual placement surface of the first yoke SB0 ... Placement reference surface of the second yoke SB1 ... Actual placement surface of the second yoke SC ... Crossing line

Claims (6)

A hub shell that rotates with the wheels and a rotor that has permanent magnets arranged around the inner circumference of the body of the hub shell.
It is non-rotatably fixed to a hub shaft that rotatably supports the wheel, and is arranged on the inner peripheral side of the permanent magnet while being housed inside the hub shell, and outputs an alternating current by the rotation of the rotor. In a hub dynamo provided with a stator having a ring-shaped coil.
The stators are arranged as a stator core on one side in the axial direction and the other side in the axial direction so as to surround the ring-shaped coil, and are arranged radially at intervals in the circumferential direction and alternately arranged in the circumferential direction. It has a plurality of first yokes and a plurality of second yokes arranged,
The first yoke is
An outer peripheral magnetic pole portion located on the outer peripheral side of the coil and having a tip extending from one end side in the axial direction to the other end side in the axial direction of the coil.
An inner peripheral magnetic pole portion located on the inner peripheral side of the coil and having a tip extending from one end side in the axial direction to an intermediate position toward the other end side in the axial direction.
A connecting portion that extends linearly on one end side in the axial direction of the coil and connects the base ends of the outer peripheral side magnetic pole portion and the inner peripheral side magnetic pole portion.
Have,
The second yoke is
An outer peripheral magnetic pole portion located on the outer peripheral side of the coil and having a tip extending from the other end side in the axial direction to one end side in the axial direction of the coil.
An inner peripheral magnetic pole portion located on the inner peripheral side of the coil and extending the tip from the other end side in the axial direction to the intermediate position toward the one end side in the axial direction.
A connecting portion that extends linearly on the other end side in the axial direction of the coil and connects the base ends of the outer peripheral side magnetic pole portion and the inner peripheral side magnetic pole portion.
Have,
The first yoke and the second yoke are configured as a laminated yoke in which a plurality of flat plate-shaped members made of a magnetic material are laminated.
When arranging the first yoke and the second yoke, the arrangement position of the first yoke and the arrangement position of the second yoke are alternately set on the outer peripheral surface of the stator at intervals in the circumferential direction.
A plane including the central axis of the hub shaft and the center in the circumferential direction of the outer peripheral surface side of the outer peripheral side magnetic pole portion of the first yoke is set as the arrangement reference surface of the first yoke, and the arrangement of the first yoke is performed. By setting a plane inclined to one side in the circumferential direction with respect to the reference surface as the actual arrangement surface of the first yoke , the outer peripheral side of the first yoke is placed on the same surface of the actual arrangement surface of the first yoke. The magnetic pole portion, the inner peripheral side magnetic pole portion, and the connecting portion are arranged.
A plane including the central axis of the hub shaft and the center in the circumferential direction of the outer peripheral surface side of the outer peripheral side magnetic pole portion of the second yoke is set as the arrangement reference surface of the second yoke, and the arrangement of the second yoke is performed. By setting a plane inclined to the other side in the circumferential direction with respect to the reference surface as the actual arrangement surface of the second yoke , the outer peripheral side of the second yoke is placed on the same surface of the actual arrangement surface of the second yoke. The magnetic pole portion, the inner peripheral side magnetic pole portion, and the connecting portion are arranged.
On the intersection of the actual arrangement surface of the first yoke and the actual arrangement surface of the second yoke, the tip of the inner peripheral side magnetic pole portion of the first yoke and the tip of the inner peripheral side magnetic pole portion of the second yoke. A hub dynamo characterized by being in contact with and. The stator has a coil bobbin made of a non-magnetic material.
The coil bobbin is
A cylindrical body around which the coil is wound and
The first flange and the second flange provided on the outer circumferences of both ends in the axial direction of the body portion,
Have,
A guide portion for positioning the first yoke on the actual arrangement surface of the first yoke is provided on the first flange by engaging one end portion in the axial direction of the first yoke.
The second flange is provided with a guide portion for positioning the second yoke on the actual arrangement surface of the second yoke by engaging the other end in the axial direction of the second yoke. The hub dynamo according to claim 1. The guide unit
A guide groove for a first yoke connecting portion provided at the axial end of the first flange and for positioning the first yoke on the actual arrangement surface of the first yoke by fitting the connecting portion of the first yoke. When,
A guide groove for a second yoke connecting portion provided at the axial end of the second flange and for positioning the second yoke on the actual arrangement surface of the second yoke by fitting the connecting portion of the second yoke. When,
The hub dynamo according to claim 2, wherein the hub dynamo has. The guide unit
A guide groove on the outer peripheral side of the first yoke that is provided on the outer peripheral surface of the first flange and that positions the first yoke on the actual arrangement surface of the first yoke by fitting the magnetic pole portion on the outer peripheral side of the first yoke. When,
A guide groove on the outer peripheral side of the second yoke provided on the outer peripheral surface of the second flange and for positioning the second yoke on the actual arrangement surface of the second yoke by fitting the magnetic pole portion on the outer peripheral side of the second yoke. When,
The hub dynamo according to claim 2 or 3, wherein the hub dynamo has. The inclination direction of the actual arrangement surface of the first yoke with respect to the arrangement reference surface of the first yoke and the inclination direction of the actual arrangement surface of the second yoke with respect to the arrangement reference surface of the second yoke are the inclination directions of the respective yokes. When
The positions of the radial outer peripheral ends of the laminated plate-shaped members located on the rear side of the first yoke and the second yoke in the inclination direction are
The claim is characterized in that the first yoke and the second yoke project radially outward with respect to the positions of the radial outer peripheral ends of the laminated plate-shaped members located on the front side in the inclination direction. The hub dynamo according to any one of 1 to 4. Avoid interference between the inner peripheral ends of the other first yoke and the second yoke that are adjacent to at least one of the inner peripheral ends of the first yoke and the second yoke in the circumferential direction on one end side or the other end side in the circumferential direction. The hub dynamo according to any one of claims 1 to 5, wherein a notch is provided.

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